Laparotomy, or surgical entry into the peritoneal cavity for abdominal surgery, is one of the most common surgical procedures performed in the United States with an estimated 4 million cases performed annually, with millions more performed worldwide. Closure of the peritoneal cavity after abdominal surgery requires careful re-approximation of the fascia (the strength layer of the abdominal wall) in order to minimize the risk of incisional hernia. Injury to the bowel during fascial closure, and the associated morbidity or mortality, may occur as a result of insufficient visualization during closure, leading to either direct needle puncture of the bowel or strangulation by suture as it is tightened out of the view of the surgeon. Currently, intraoperative maneuvers used to prevent visceral injury include use of a metal malleable retractor or the PVC Glassman Visceral Retainer to displace and shield the bowel. However, these strategies are only partially effective as neither device completely shields the viscera. More problematically, they must be removed from the peritoneal cavity prior to closure of the final few centimeters of fascia, leaving the bowel unprotected and vulnerable to injury during this most crucial phase of the operation. Inadequate visualization and protection of the bowel further contribute to increased rates of hernia recurrence as surgeons may incorporate suboptimal fascial “bites” to decrease the risk of bowel injury during closure. The mass of bowel is also typically wider than the retractor, which leads to ineffective displacement
Another commonly used instrument in abdominal surgery is the Glassman Visceral Retractor or “FISH”. This flexible device is used to shield the bowel from inadvertent injury and is quite popular. However, because the “FISH” device is made of plastic, it must be removed from the peritoneal cavity prior to tying the final several sutures, leading to “blind” suture tying, which often results in bowel loops becoming ensnared. Further, the device is often not wide enough to prevent bowel from entering the surgical field, a design flaw resulting from the need to keep it thin enough so that it can be removed from the peritoneal cavity through a relatively small opening prior to tying of the last several fascial sutures. Ultimately, the major drawback to both the current malleable retractor and “FISH,” respectively, is the inherent risk they pose as retained instruments during abdominal surgery, which leads to significant postoperative morbidities, including bowel obstruction, perforation, sepsis, reoperations, and even death. In fact, retained surgical instruments are exceedingly common with an incidence between 0.3 and 1.0 per 1,000 abdominal operations despite their avoidable nature (e.g., Stawicki, S. P., et al., Retained surgical foreign bodies: A comprehensive review of risks and preventive strategies, Scand. J. Surg. 2009, 98, 8-17).
Furthermore, beyond the difficulty posed by fascial closure, post-operative bowel adhesions (the pathologic fibrotic bands that commonly develop after surgical manipulation), are a significant contributor to patient morbidity and mortality. To enumerate, abdominal post-operative adhesions occur in an alarming 90% of abdominal surgery patients, and are a major cause of bowel obstruction, bowel perforation, chronic pelvic pain, and infertility. Medical complications from abdominal adhesions are extraordinarily high with between 30% and 75% of abdominal surgery patients requiring secondary surgery to correct conditions directly related to adhesion formation, with the economic cost of abdominal tissue adhesions and their treatment exceeding $2.1 billion annually in the United States alone (e.g., Ellis, H., et al., Adhesion-related hospital readmissions after abdominal and pelvic surgery: a retrospective cohort study. Lancet. 1999, 353, 1476-1480; Ray, N. F. et al., Abdominal adhesiolysis: inpatient care and expenditures in the United States in 1994. J Am Coll Surg. 1998, 186, 1-9. Given the above limitations of surgical instruments currently employed in abdominal surgery, there would a significant benefit in a surgical barrier that could reduce the complications associated with abdominal surgery and to better facilitate fascial closure.